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Eliminate dead symlinks interactively in /usr/ recursevely
Its not mine... I get from textlive migration in gentoo : http://www.gentoo.org/proj/en/tex/texlive-migration-guide.xml

FInd the 10 biggest files taking up disk space

Create a mirror of a local folder, on a remote server
Create a exact mirror of the local folder "/root/files", on remote server 'remote_server' using SSH command (listening on port 22) (all files & folders on destination server/folder will be deleted)

count the number of specific characters in a file or text stream
In this example, the command will recursively find files (-type f) under /some/path, where the path ends in .mp3, case insensitive (-iregex). It will then output a single line of output (-print0), with results terminated by a the null character (octal 000). Suitable for piping to xargs -0. This type of output avoids issues with garbage in paths, like unclosed quotes. The tr command then strips away everything but the null chars, finally piping to wc -c, to get a character count. I have found this very useful, to verify one is getting the right number of before you actually process the results through xargs or similar. Yes, one can issue the find without the -print0 and use wc -l, however if you want to be 1000% sure your find command is giving you the expected number of results, this is a simple way to check. The approach can be made in to a function and then included in .bashrc or similar. e.g. $ count_chars() { tr -d -c "$1" | wc -c; } In this form it provides a versatile character counter of text streams :)

Quick HTML image gallery from folder contents
Setting: You have a lot of jpg files in a directory. Maybe your public_html folder which is readable on the net because of Apache's mod_userdir. All those files from the current folder will be dropped into a file called gallery.html as image tags that can be viewed within a web browser locally or or over the Internet. Original: $find . -iname "*.jpg" -exec echo "" >> gallery.html \;

Generate a list of items from a couple of items lists A and B, getting (B - A ) set
ItemsListtoAvoid (A) could be a list of files with a special characteristic to exclude. It can be a result of previous processing list, ex. a list of files containing a special string. AlItemsList.txt (B) Is a complete list of items including some or all items in A. $Difference is saved in ItemsDifference.txt

FInd the 10 biggest files taking up disk space
Often you need to find the files that are taking up the most disk space in order to free up space asap. This script can be run on the enitre filesystem as root or on a home directory to find the largest files.

Sort a one-per-line list of email address, weeding out duplicates

Convert Squid unixtime logs in human-readable ones
On-the-fly conversion of Unix Time to human-readable in Squid's access.log

Calculate days on which Friday the 13th occurs (inspired from the work of the user justsomeguy)
Friday is the 5th day of the week, monday is the 1st. Output may be affected by locale.


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